Expansible and collapsible element for thermostatic and pressuresensitive devices



H. c. MALLORY.

EXPANSIBLE AND COLLAPSIBLE ELEMENT FOR THERMOSTATIO AND PRESSURESENSITIVE DEVICES. APPLICATION FILED APR.22. 1914- RENEWED DEC 5. 1919.

1,366,473, Patented Jan. 25, 1921.

2 SHEETS-SHEET 1.

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WAdMfi. J izdd m H. C. MALLORY. EXPANSIBLE AND COLLAPS'IBLE ELEMENT FORTHERMOSTATIC AND PRESSURE SENSITIVE DEVICES.

APPLICATION FlLED-APR.2Z, I914. RENEWED DEC. 5.1919.

Patented Jan. 25, 1921.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

HARRY O. MALLOBY, OF BELLPORT, NEW YORK.

AND ranesuan- SENSITIVE nnvrcns.

Specification of Letters Patent.

Patented Jan. 25, 1921.

Application filed April 22, 1914, Serial No. 888,593. Renewed December5, 1919. Serial No. 342,862.

p are designed for use in fluid pressure motors, steam traps, expansionomts, damper regulators, and the like.

A full understanding of the inventlon will be attained from thefollowing description illustrating its several features in a preferredform, taken in connection w th the accompanying drawings andspecifically pointed out in the appended claims.

In; the drawing, 7

Figure 1 is a cross-section of a portlon of a thermostat showing anexpansible and collapsible vessel of the bellows type attached to ahead;

Fig. 2 is a cross-section of another type of thermostat showing amodified method of attaching the element;

Fig. 3 illustrates a method of attaching and sealing another type ofelement to its holding member;

Fig. 4 shows a completed element of the same type, ready for attachmentto its hold- 0 member;

in Fig. 5 is an illustration of a further modishowing a modifiedflexible element of the diaphragm type and a method of attaching it tothe valve casing and the valve head; and

Fig. 10 is a cross-section of a thermostatic steam trap employed invacuum heating systems showing a further modifiedv method of attachingan element to the tubes.

In thermostatic and pressure sensitive devices, such as fluid pressuremotors, steam traps, damper regulators, thermostats and the l1ke, wherean expansible and collapsible metal element is employed to transmitmotion in response to fluctuations of temperature or pressure it isnecessar that the joint at the po nt of attachment 0 the element to theparticular type of device with which it 1s employed be tight againstfluid pressure and that the joining process not weaken the element atthis point. In such devices one end of the element is usually held rigidand the other end or head is movable and attached to some part of thedevice for the transmission of power or motion, for instance, to thevalve member of a thermostatic steam trap. The strain at the joint issometimes very great at the period of maxlmum expansion of the elementand rupture is accordingl exceedingly liable to occur at a weakene pointin the element. It has formerly been the practice to employ solder or toform a brazed joint for attaching theelement. This method has been foundexceedingly unsatisfactory for the reason that a different temper isthereby imparted to the thin wall of the element at the point ofattachment and consequently the resistance of the metal to strain ismaterially weakened. Although the employment of solder is necessary insome cases when it is. desired that the joint be hermetically sealed, Ihave discovered that by firmly pressing the end of the element into someportion of the device to which it is attached and so securing theelement, that it is possible to have the sealing action entirelyindependent of the attaching action. In other words, the element isretained in its position solely because of the pressure "employed andits contact with the part of the device and not because of any actionexerted bythe solder, its effect being only to seal the jointhermetically. In this way, I have altogether obviated interference anddestruction of the temper of the metal and have accordingly secured amuch stronger and more satisfactory joint, without dispensing with thebeneficial effects accruing from the employment of solder.

In the forms of my invention illustrated in Figs. 1 and 2, the aboveresult is attained in the following manner: For purposes ofillustration, I show a corrugated vessel 1 of the bellows type which isgenerally emplo ed in thermostatic steam traps, having -a c osed end orhead 2 and an openend 3 which is attached to a part of the trap, forinstance, the head piece 4 to form a thermostat or chamber confining avolatile fluid sensitive to changes in' temperature. The head piece isprovided with a screw-threaded portion 5 for securing the thermostat inposition in the trap and with a tail piece 6 projecting into thechamber. As shown, the open and closed ends of the flexible vessel arereinforced or strengthened by being made greater in cross-section thanthe in-- termediate corrugated portion 7 which is comparatively thin.This construction of vessel is preferably obtained by drawing it from asuitable metal blank in the form of a shell having a closed end, in sucha way that the various thicknesses mentioned are obtained and then bycorrugating in any well known manner the intermediate thin portion. Itis preferable that the thick portions of the shell taper gradually intothe intermediate thin portion. Thus between the thin part whichisresilient and the thick part which is rigid the boundary lies in thepart of tapered thickness, and by making this part tapered instead ofabrupt this transition region is somewhat diffused and'a tendency tobreak apart there is obviated.

In the form shown in Fig. 1, the head piece is provided with an annularcurved depression 9 into which the thick open end 3 is clamped orpressed into a firm frictional contact. The vessel is thus supportedsolely by contact with the head piece, and the use of solder at thepoint of attachment with its attendant disadvantages is eliminated. Thejoint will be found exceedingly strong and capable of resistance to fargreater pressures than has been found in preexisting structures, as wellas simple in construction and eas to make.

11 Figs. 3 and 1, I have illustrated modifications of vessels in whichthe open thick end is flared to form an outwardly project ing annularflange 80 which is adapted to be rolled around and over the flange 13 ofthe type of head piece or plug 7 9 shown in Fig. 3. The head piece maybe similarly provided with a screw-threaded lug 12 for attachment to thecasing of the trap. Except for the flaring operation, the method ofmaking the vessel is similar to that employed with the forms shown inFigs. 1

and 2. In the forms shown in Figs. 3, 1, and

5 the head or closed end 2 is flat.

The present type of vessel will be found particularly advantageous whenit is desired to make a hermetically sealed joint which is effected byrolling the flared end 80 over the flange 13' in such manner that aspace 14: is left between the end of the vessel and the inner wall ofthe flange 13 which may be filled withv solder. If the soldering opera-.tion is carried out with the vessel immersed in water, all disturbanceof the temper of the metal at its end is prevented and consequentweakening of the joint avoided. It will be noted that the solder playsno part in maintaining the vessel on its support, the effect beingsolely to render the joint hermetically sealed.

Figs. 5, 6 and 7 illustrate modifications in which only the head orclosed end of the vessel is greater in cross-section than theintermediate portion. As shown in Fig. 6, the closed end may be taperedgradually into the thin intermediate portion of the metal leaving acentral portion 15 in the end of greatestrigidity and an annular portion16 gradually increasing in flexibility until it merges into the thinintermediate portion of the metal. The head or end being integralwith'the corrugated portion of the vessel, the use of a seam isdispensed with and the vessel is thereby rendered much stronger, apeculiarly valuable feature in hermetically sealed vessels as suchdevices must be made as seamless and jointless as possible. The greatlyreduced cost of manufacture as compared with presentdevices of thischaracter is another advantage which must not be overlooked.

Another novel feature lies in the fact that the thick end may be soshaped by drawing the metal as to form a valve head 17 integral with thevessel (see Fig. 7), reducing any liability of the thermostat to get outof order and requiring fewer repairs because of the reduction in thenumber of parts.

In Fig. 8 I show a vessel having its thick closed end shaped to form alug 18, towhich a valve head may be attached, either by screw-threadingthe lug or in any other well known manner. In Fig.2 the lug 18' is shownas being pressed into the recessed valve head, the end of which isfirmly clamped around the lug.

Another method of attaching the open end of the vessel is illustrated inFig. 3, which shows the end 2 pressed into a groove 19 in an orifice inthe valve bonnet 20 by a cup shaped head 21 having an annular flange 78which is forced into the same groove. It will be noted that the thickopen ends of the vessels may be screw-threaded, if so desired.

In Fig. 9 there is illustrated a diaphragm type of thermostat used in asteam trap of valves which consists of a valve casing 48 adapted to beconnected to a regulator by a screw thread as shown at 49 and having aninterior screw threaded portion 50adapted to be connected to an air andwater escape. The diaphragm 51 is secured in the valve casing bypressing its open end which in this case is of the same cross section asin the intermediate corrugated portion, into an annular groove 52 formedin the flange groove thussecurely holding the diaphragm in its position.An annular groove 55 is provided in the flange in case it is desired toemploy solder for the purpose of hermetically sealing the joint. Theadvantages of this construction have heretofore been fully explained indetail and consequently, it is not necessary to enlarge upon them. Thevalie head 56 which is adapted when the diaphragm is expanded to seatover the opening 57 is secured to the closed smaller end of thediaphragm by forming a recess in its upper face and clamping the ends ofthe recess around and over the reinforced end 57 of the diaphragm.Reinforcement is obtained by incorporating a metal disk 58 in the firstcorrugation at the time when the corrugating process is carried out.

Fig. 10 illustrates a further application of my invention, in this caseto a thermostat steam trap such as is designed for use in connectionwith vacuum heating systems. In this case the flexible element employedis of the bellows type as shown at 59 and has its open end secured in agroove 60 in the valve bonnet 61 by means of the tubular shaped member62 which projects in the diaphragm and is provided with an expandedportion 63 entering the groove 60 and exerting pressure on the end ofthe flexible vessel to maintain it in position- A perforated metal cap64 is placed over the member 62 to prevent dirt from entering theinterior and at the same time permit free circulation of air. Avalvestem 65 is secured to the closed end of the vessel in the samemanner as is shown in Fig. 9. The valve body 66 is connected to theradiator by means of a union nut 67 and has a threaded connection 68 tothe escape or the return pipe.

The operation of thermostatic steam traps of the two types abovereferred to is so well known in the art that it is not thought necessaryto enter into any detailed description herein.

lVhile I have herein shown and described certain forms and constructionsof elements whereby variations in atmospheric pressure in temperaturemay be utilized and have illustrated various methods of application ofsuch elements, it will be understood that my invention is not limitedeither to any specific form of element or to any specific application,and that the inventive idea is capable of wide modification and may beembodied in many forms without departing from the scope thereof.

In the following claims I employ the term flange -to designate theprojecting open end portion of the shell, whether it projects out as aplane annulus as in Fig. 4, or as a cylindrical extension as in Figs. 1and 2.

\Vhat is claimed is: l. A wall for an expansible and collapsible elementhaving a corrugated main portion and an integrally reinforced closed endjoining the corrugated part of the wall by a tapering portion.

2. A wall for an expansible and collapsible element formed of resilientmetal having a flexible intermediate portion and an integral end portionof greater cross-section than said intermediate portion, the end portionand the intermediate portion being joined by a portion of taperingthickness.

3. A wall for an expansible and collapsible element formed by pressurefrom seamless metal having a resilient intermediate portion andintegrally reinforced closed end portion.

4. A wall for an expansible and collapsible element having a flexibleintermediate portion and a reinforced flanged open end portion taperinginto the flexible intermediate portion.

5. An expansible and collapsible element having a thin resilient wall ofseamless metal and a relatively thick closed end of greatercross-section tapering into the resilient wall.

6. A wall for an expansible and collapsible vessel having a flexibleintermediate portion and with one end open and the other end' closed,the open end being surrounded by a flange portion, and said flangeportion being reinforced, the reinforcement tapering into the flexibleintermediate portion.

7. A wall for an expansible and collapsible vessel having a flexibleintermediate portion surrounded by a flange portion, said flange portionbeing reinforced, the reinforcement tapering into the flexibleintermediate portion.

8. A wall for an expansible and collapsible vessel having a flexibleintermediate portion and with one end open and the other end closed, theopen end being surrounded.

by a flange portion, said flange portion being reinforced, and theclosed end of said wall also being reinforced, the reinforcementtapering into the flexible intermediate portion.

9. A wall for an expansible and collapsible element having a flexibleintermediate portion and a reinforced flanged open end portion taperinginto the said intermediate portion.

10. A wall for an expansible and collapsi ble element having a flexibleintermediate portion and an integrally reinforced flanged open endportion tapering into the said intermediate portion.

In testimony whereof I aflix my signature, in presence of two witnesses.

. HARRY C. MALLORY.

Witnesses:

EnWAm) S. WHITE, G. N. KERR.

